Soal OSN IPA SMP Biologi Tahun 2023 (Part-1)

Summary

This video provides a detailed walkthrough of the 2023 OSN (National Science Olympiad) biology questions. The presenter discusses various biological concepts such as the characteristics of living organisms, genetic inheritance, cell biology, and ecological diversity. Key topics covered include gutation, the role of melatonin in regulating circadian rhythms, autosomes, and the differences between prokaryotic and eukaryotic cells. Through explanations of genetics, plant physiology, and human biology, the video engages viewers by breaking down complex biological topics in a clear and approachable manner. The presenter also highlights some errors in the questions to ensure clarity.

Takeaways

• 😀 The first question discusses various characteristics of living organisms, like gutation (excretion) and iritability (response to stimuli). The correct sequence for the answer is 3, 4, and 2.
• 😀 Autosomes in humans refer to body chromosomes, and the correct number is 44 chromosomes or 22 pairs.
• 😀 Melatonin regulates the circadian rhythm and is produced by the anterior part of the pineal gland. The question discusses the connection between these two points, which does not establish cause and effect correctly.
• 😀 The immune system in humans involves several white blood cells, including leukocytes and lymphocytes. In insects, immunity is managed by hemocytes.
• 😀 The inheritance of albinism in humans is explained using a Punnett square, showing a 50% chance of children being albino, and a 25% chance of a female albino child.
• 😀 Variations in species can be genetic or environmental, and both types contribute to physical, behavioral, and genetic diversity within a species.
• 😀 The epidermis and cortex of plants have distinct characteristics, such as thick cell walls and the presence of parenchyma cells in the cortex, and compact cells in the epidermis.
• 😀 Saliva is produced by three main salivary glands: parotid, submandibular, and sublingual, playing an essential role in the digestive system.
• 😀 Biodiversity in a habitat is measured by calculating the species diversity, represented by the ratio of species to total individuals in an area.
• 😀 Chromosomes with centromeres at the median position are called metacentric chromosomes, forming a V-shape.
• 😀 Polydactyly is a genetic disorder caused by an autosomal dominant gene, leading to extra fingers or toes, and the relationship between the cause and effect of this disorder is not clearly explained in the provided rationale.

Q & A

What is the process called when fluid is released from the tip of a guava leaf?

The process is called 'gutasi,' which is the excretion of excess water in plants, specifically from the tip of leaves.

What does the closing of the sensitive plant's leaves indicate?

The closing of the sensitive plant's leaves is an example of 'irritability,' which is a response to stimuli or sensitivity to touch.

Which characteristic of living organisms is shown by the appearance of flowers in rice plants?

The appearance of flowers in rice plants is an example of 'reproduction,' a characteristic of living organisms related to development and propagation.

What type of adaptation is shown by the presence of thorns on a cactus?

The thorns on a cactus are an example of 'adaptation,' a survival mechanism to protect the plant from herbivores and reduce water loss.

What is the correct number of autosomes in humans?

Humans have 44 autosomes, or 22 pairs of autosomes, which are non-sex chromosomes.

What role does melatonin play in the human body?

Melatonin regulates the circadian rhythm, which controls the sleep-wake cycle. It is produced by the pineal gland.

What is the function of leukocytes in the human immune system?

Leukocytes, or white blood cells, are part of the immune system and are responsible for defending the body against infections and diseases.

What is the genetic explanation behind the inheritance of albinism in offspring?

Albinism is inherited when one parent passes on a recessive allele for albinism (aa). In the case of a heterozygous normal mother (Aa) and an albino father (aa), there is a 50% chance their child will inherit the albino trait.

How does genetic variation occur in a species?

Genetic variation in a species occurs due to differences in genes inherited from parents, as well as environmental influences that can affect traits.

What is the function of the epidermis in plants, and what is its characteristic?

The epidermis in plants is the outermost layer of cells that protect the plant. It has tight cell walls with little to no space between cells, and it helps to reduce water loss.